As the ruling Liberal Democratic Party holds its leadership election Wednesday, a key question for many Japanese and outside observers remains the candidates’ positions on China.

While there appears to be little space between the two leading candidates, former Foreign Minister Fumio Kishida and the vaccine czar and administrative reform minister, Taro Kono, there is deep concern among parts of the LDP, including senior leaders, about Kono on this issue. It will have implications for governing if Kono does indeed win the party ballot and the LDP prevails in the national election that will follow.

China is a rival with Japan for regional leadership and has irredentist claims to Japanese territory (the Senkaku Islands and even Okinawa in more expansive moments). Japanese are nervous about Beijing’s argument that it controls the South China Sea, which straddles the sea lanes that carry this country’s vital trade. A conflict with Taiwan to realize Beijing’s long-held dream of reunification with China is considered a threat to Japan’s own security, one that is growing ever more real and immediate.